Investigations concerned with absolute thresholds have often alluded to the organisms internal noise to account for experimental data. In short, internal or physiological noise has been used as an explanatory concept in a post hoc manner with little data to support the idea that internal noise acts as a masking stimulus. This proposal outlines some techniques and procedures designed to yield information on the relationship between internal noise and auditory function. By defining internal noise operationally as a combination of aural noise, physiological noise, and neural noise, one can begin to examine the relationship experimentally. The proposed research is important in that it will provide a more refined understanding of how the auditory system processes inputs near threshold (useful in clinical audiometry and the diagnosis of hearing impairments) and further data relevant to theoretical issues concerned with binaural signal processing and internal (physiological and aural) noise.